django-admin startproject middleware
cd middleware
django-admin startapp app

# middleware/settings.py
# INSTALLED_APPS最后添加 app
INSTALLED_APPS = [
 'app',
]

# 创建app/middleware.py并编辑
from django.http import JsonResponse


class CustomMiddleware:
 def __init__(self, get_response):
  print("程序启动时执行, 只执行一次")
  self.get_response = get_response

 def __call__(self, request):
  print("中间件开始")
  response = self.get_response(request)
  print("中间件结束")
  return response

 def process_view(self, request, view_func, view_args, view_kwargs):
  print("请求实际函数前执行")

 def process_exception(self, request, exception):
  print("程序异常时执行")
  return JsonResponse({"msg": exception.args[0], "code": -1})

MIDDLEWARE = [
...
'app.middleware.CustomMiddleware'
]

# app/views.py
from django.http import JsonResponse


def json_response(request):
 print('json_response')
 err = 3 / 0
 return JsonResponse({"msg": "ok", "code": 0})

# middleware/urls.py

from app.views import json_response, view_response

urlpatterns = [
 ...
 path("view", view_response)
]

# 在中间件函数process_view中添加
print("path: {}; method: {}; data: {}".format(request.get_full_path(), request.method, request.body or ''))